NaCl Box Encryption works just like GPG. Its encryption is as good, if not better than GPG. As with GPG, you have a public key and a secret key.
A NaCl Box public key is much smaller, only 64 bytes long. You exchange your public key with those whom you wish to communicate with.
The code used to create the box-master.exe encryption program can be found at: https://github.com/rovaughn/box
A.
To get setup, click the GEN
button to bring up the Generate key window.

(Note: 'User' and 'identity' refers to your key(s) and 'peer' refers to received public keys.)
The default User name is 'self'. However, you can assign a User key a different name. You can choose to use only one User key to encrypt
with or you can create a different User key for each peer you communicate with. After generating a key, the public key will display in
the 'Generated User Public Key' box. Both a public and private key will have been generated.
B.
Click the Add button to import a Peer's key that has been sent to you.

To add the Peer's public key, first assign the key a peer key name that identifies that person. Then place the received public key in the
peer key box and click the 'Import' button.
C.
Click the Keys button to show your available keys.

In the example, you have 6 peer keys named ann, j.jones, john, les.smith, w.wood, and williams, and 3 User key (identity) named self, self2, and self3.
To capture your 'self' public key to the clipboard, click on the 'self' key line and right click on the window. Then click the
'Copy Public Key' menu item. Your Public Key can then be emailed to others you wish to communicate with.
To delete a key, click on the line you wish to delete and click Delete Key.
To encrypt your keys, right click the 'Keys' button and check the 'Encrypt Keys' menu item. Upon closing the program, you will be prompted for a password
(or passphrase). Your keys are encrypted using TwoFish and stored in the '.UserKeys' folder. The key files that were encrypted are then scrubbed and deleted.
Upon starting the program again, you will be prompted for
the password. You will not be prompted again upon closing. To reset your password, start the program, uncheck 'Encrypt Keys', re-check 'Encrypt Keys',
and enter the new password at program close.
D.
Setup main interface to encrypt.

Last, uncheck the 'Lock' check box on the right side of the main interface. Enter into one of the five top windows your User key name you wish to use to
encrypt your message with, followed by a slash '/', and then the peer key name you wish to encrypt your message to. Re-check the 'Lock' check box.
Each window will hold up to five key combination lines. The last window is not limited.
To encrypt a message, simply click the line in the appropriate windows. The message will be encrypted and placed into the main window.
To decrypt a message, click the Decrypt button at the bottom of the interface.
To encrypt or decrypt a file, click the 'File' button and then follow the encrypt and decrypt instructions above.
Note: If an encoded non-text file is received in an email (.exe, .png, etc), paste the encoded data into the main window, right click the main window, and save
the encoded data to a file. Then click the File button and the Decrypt button.
E.
Click the Params button to bring up the parameters window.

https://github.com/inwtx/NaClBoxEncryption/